Wilms Tumor
Stage I (43% of patients)
Stage II (23% of patients)
Stage III (23% of patients)
Stage IV (10% of patients)
Stage V (5% of patients)
Stage I-IV Anaplasia
Current Clinical Trials

Wilms Tumor

The stage is determined by the results of the imaging studies and both the surgical and pathologic findings at nephrectomy and is the same for tumors with favorable or anaplastic histology. Thus, patients should be characterized by a statement of both criteria (for example, stage II, favorable histology or stage II, anaplastic histology).[1,2]

The staging system employed by the National Wilms Tumor Study Group and incidence by stage is outlined below.[2]

In stage I Wilms tumor, all of the following criteria must be met:

• Tumor is limited to the kidney and is completely resected.



• The renal capsule is intact.



• The tumor is not ruptured or biopsied prior to removal.



• No involvement of renal sinus vessels.



• No evidence of the tumor at or beyond the margins of resection.

 [Note: For a tumor to qualify for certain therapeutic protocols as stage I, regional lymph nodes must be examined microscopically.]

In stage II Wilms tumor, the tumor is completely resected, and there is no evidence of tumor at or beyond the margins of resection. The tumor extends beyond the kidney as evidenced by any one of the following criteria:

• There is regional extension of the tumor (i.e., penetration of the renal sinus capsule, or extensive invasion of the soft tissue of the renal sinus, as discussed below).



• Blood vessels within the nephrectomy specimen outside the renal parenchyma, including those of the renal sinus, contain tumor.

 [Note: Rupture or spillage confined to the flank, including biopsy of the tumor, is no longer included in stage II and is now included in stage III.]

In stage III Wilms tumor, there is residual nonhematogenous tumor present following surgery that is confined to the abdomen. Any one of the following may occur:

• Lymph nodes within the abdomen or pelvis are involved by tumor. (Lymph node involvement in the thorax or other extra-abdominal sites is a criterion for stage IV.)



• The tumor has penetrated through the peritoneal surface.



• Tumor implants are found on the peritoneal surface.



• Gross or microscopic tumor remains postoperatively (e.g., tumor cells are found at the margin of surgical resection on microscopic examination).



• The tumor is not completely resectable because of local infiltration into vital structures.



• Tumor spillage occurs either before or during surgery.



• The tumor was biopsied (using tru-cut biopsy, open biopsy, or fine-needle aspiration) before removal.



• The tumor is removed in more than one piece (e.g., tumor cells are found in a separately excised adrenal gland; a tumor thrombus within the renal vein is removed separately from the nephrectomy specimen).

In stage IV Wilms tumor, hematogenous metastases (lung, liver, bone, brain, etc.), or lymph node metastases outside the abdominopelvic region are present. (The presence of tumor within the adrenal gland is not interpreted as metastasis and staging depends on all other staging parameters present.)

In stage V Wilms tumor, bilateral involvement by tumor is present at diagnosis. An attempt should be made to stage each side according to the above criteria on the basis of the extent of disease. The 4-year survival is 94% for those patients whose most advanced lesion is stage I or stage II, and 76% for those whose most advanced lesion is stage III.[3]

Anaplastic histology accounts for about 10% of Wilms tumors. Children with anaplastic tumors have a worse prognosis than children with favorable histology when compared stage to stage. These tumors are more resistant to the chemotherapy traditionally used in children with Wilms tumor (favorable histology).[4]

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with Wilms tumor and other childhood kidney tumors. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References

1. Wilms' tumor: status report, 1990. By the National Wilms' Tumor Study Committee. J Clin Oncol 9 (5): 877-87, 1991.  [PUBMED Abstract]
   
   
2. D'Angio GJ, Breslow N, Beckwith JB, et al.: Treatment of Wilms' tumor. Results of the Third National Wilms' Tumor Study. Cancer 64 (2): 349-60, 1989.  [PUBMED Abstract]
   
   
3. Ritchey ML, Coppes MJ: The management of synchronous bilateral Wilms tumor. Hematol Oncol Clin North Am 9 (6): 1303-15, 1995.  [PUBMED Abstract]
   
   
4. Dome JS, Cotton CA, Perlman EJ, et al.: Treatment of anaplastic histology Wilms' tumor: results from the fifth National Wilms' Tumor Study. J Clin Oncol 24 (15): 2352-8, 2006.  [PUBMED Abstract]
   
   

Back to Top

< Previous Section  |  Next Section >